package days48;

import java.util.Locale;
import java.util.Scanner;

public class day18 {
    public static void main1(String[] args) {
        Scanner scanner=new Scanner(System.in);
        String str=scanner.nextLine();
        String c=scanner.next();
        str=str.toLowerCase(Locale.ROOT);
        c=c.toLowerCase(Locale.ROOT);
        int count=0;
        for (int i = 0; i < str.length(); i++) {
            if (str.charAt(i)==c.charAt(0)){
                count++;
            }
        }
        System.out.println(count);
    }

    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        int n=scanner.nextInt();
        int[][]arr=new int[n][2*n+1];
        arr[0][n]=1;
        for (int i = 1; i < n; i++) {
            for (int j = 1; j < 2*n; j++) {
                arr[i][j]=arr[i-1][j]+arr[i-1][j-1]+arr[i-1][j+1];
            }
        }
        for (int i = 0; i < arr[n-1].length; i++) {
            if(arr[n-1][i]%2==0){
                System.out.println(arr[n-1][i]);
                return;
            }
        }
        System.out.println(-1);
    }
}
